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Urtrrnn '8rarns Farnwr @triest LUTHER R. FAUGHT, OF PHILADELPHIA,PENNSYLVANIA.

BORlNG=TOOL GPECFICATION forming part of Letters Patent No. 302,831,dated July 29, 1884.

Application filed December 29, 1883.

To @ZZ whom, i6 may concern:

Be it known that I, LUTHER R. FAUGHT, of the city and county ofPhiladelphia, in the State of Pennsylvania, have invented certain newanduseful Improvements in Boring-Bars, of which improvements thefollowing is a speeiiication.

My invention relates to boring-bars of the class having two transverseslots at right angles one to the other, each adapted to receive a toolor cutter, instances of which are' illus trated in Letters Patent of theUnited States Nos. 241,481, 253,523, and 289,522, granted and issued tome under dates of May 17 1881, February 14, 1882, and December 4, 1883,respectively.

The object of my present invention is to enable a higher standard ofstrength and durability of the cutters to be attained; and, further, toprovide effective and desirable means for securing` the same inposition, with the eapaeity of ready and convenient removal andreplacement, as may be required.-

The improvements claimed are hereinafter fully set forth.

l'n the accompanying drawings, Figures 1 and 2 are vertical longitudinalcentral sections at right angles one with the other, respectively,through the lower portion of a boring-bar embodying features of myinvention, Fig. 3, a transverse section through the saine at the line xx of Fig. 2; Fig. 4, a bottoni view of the shoulder-block detached; andFigs. 5 and 6, longitudinal central sections at right angles one withthe other, respectively, showing a modification of the means forsecuring the cutters.

1n the practice of my invention the' boring bar Ais, similarly to thoseof my several Letters Patent aforesaid, provided with two trans verse ordiametric slots, a and a,which, in the case of a vertical bar,or oneprojecting from a spindle, as in Figs. 1, 2, and 3, are located adjacentto its lower end, and in horizontal bars having supports at cach end, asin Figs. 5 and 6, may be arranged in pairs at desired intervals in thelength of the bar. The'width of said slots is, as in the Letters Patentreferred to, such as to admit easily the boring-tools or cutters, andtheir depth is greater than the depth thereof, so as to allow of theintroduc- (No model.)

tion, clamping, and removal of the same, as

required. In lieu, however, of employing two cutters of equal depth andrecessing or notching each of them centrally to bring theircutting-points as nearly as possible in the saine plane, as in my priorconstructionsd provide, under iny present invention, a cutter having acentral opening or passage which is closed at bot-h its ends, and ashallower cutter hav-` ing no recess or opening, and adapted to bepassed through the opening of the cutter first nained. In lieu, further,of forming end shoulders upon the cutters and supporting the saineagainst peripheral dies in the bar, 1 construct the cutters with centralbearing projections or shoulders abutting against a central bearing,either Xed or removable in the boring-bar, and secure both cutters inposition by a single clamping screw or key, all as presently hereinafterto be described.

Referring to Figs. 1 to 4., inclusive, the transverse slots d and a ofthe boringbar A are suited, respectively, to receive a cutter, E, and acutter, F, which is shallower than the cutter E to such a degree as topass freely through a transverse opening or passage, e,

formed therein. The passage c, which is closed completely at each end bythe metal of the cutter, is preferably of substantially circular forin,with a attened throat, c', at bottoni, which bears against the lowerside of the cutter F. In cutters of smaller size the width of thepassage c may be reduced as desired, to maintain proper strength incorrespondence with reduced lengthof the cutter, so that the passageshall be of rectangular or elliptical form, with strong curves orfillets at top and bot-tom. The cutters E and F have plain or straightfaces at top, upon which are formed central bearing projections orshoulders, cl and f, respectively, the bearings of which are formed in ashoulder-block, B, of hardened steel, inserted and fitted tightly in theupper end of acentral opening, ai, in the bar A. The block B has atransverse recess, b, on its lower side to receive the deeper cutter E,the shoulders e'Z of which bear against the top of the recess, and theshoulders f of the cutter F bear against th'e lower ends of the jaws b'on each side of the recess, separate and independent bearing seats orfaces being thus pro- IOO -20 position in the bar.

vided by the shoulder-block B for each of the cutters E and F. In orderto enablethe shoulder-block to be withdrawn from its position whenrequired, a female thread, b2, is cut centrally within it from therecess b to its upper end, the clear opening ofthe recess being not lessthan the outer diameter of saidthread, and by inserting a correspondingscrew of sufficient length to bear against the top of the 1o opening a2,in which the shoulder-block is fitted, the latter may, by the rotationof the screw, be readily backed out and withdrawn. The opening a2, whichextends withoutreduction of diameter to the lower end of the boring-bar,is threaded at and adjacent to its lower end, to engage the vexternalthread of a bushing, C, which is internally threaded to act as the :uutof a central clamping-screw, D, by which the cutters are secured inworking The cutter E being placed in its slot c, and the cutter Finserted Vin its slot a and passed through the opening e of the cutterE, and each cutter being adjusted to project for equal distances fromthe bar on both sides of its axis, the clampingscrew D is screwed to atight bearing against the lowerside of the cutter E, thereby forcing theshoulders e2 of said cutter against the bearings at the top of therecess b ofthe shoulder- 3oy block B. The tightening of theclampingscrew D causes the throat e of the passage to bear coincidentlyagainst the lower side of the cutter F, and to force the shoulders fthereof against their bearings on the lower ends of the jaws b of theshoulder-block, the clampingscrew thus acting, by its direct thrust, tofix and hold both the cutters. The surface of the throat e of the cutterE and the correspond ingabutting surface of the cutter F are curved orsegmental in central transverse section, as shown, so that a centralpivotal bearing, through which accurate adjustment may be obtained, isafforded. An annular recess is formed in the upper portion of thebushing and is filled with suitable packing, c, which surrounds theupper unthreaded portion of the clampingscrew D and protects-the threadsthereof from the contact of borings or other foreign matter.

The construction shown in Figs. 5 and 6 is one which is speciallyadaptable to boringbars supported at both ends, but which, as indi'catedby dotted lines in Fig. 6, is likewise vapplicable to a boring-bar whichhas no lowerv 55 end support, as hereinabove described. The cutters Eand F constitute one pair of a series located at desired distances apartin the length of the bar A, and fitting in transverse slots a c', atright angles one tothe other, each of said slots being in line andcommunicating with two of a series of four longitudinal grooves orrecesses, a,in the bar. In lieu ofthe shoulder- `block removablebearings before described, fixed bearings are provided for the shouldersof the cutters in the metal of the bar, the shoulders or bearingprojection e2 of the cutter E fitting against central bearings in avtransverse opening, g, in thebar A, and the shoulders fof the cutter'Ffitting against similar bearings in one side of the slot a. 'Ihe cuttersare secured in position by a transverse key or wedge, G, which, incombination with the cutters E and F, performs the same function as andacts as the mechanical equivalent of the clamping-screw D, beforedescribed. The key G, which is not, per se, claimed herein as of myinvention,\vill be set forth in another application for Letters Patentto be filed in due timeV by me.

It will be obvious that my improvements are equally applicable inconnection with one or a pair of cutters, and that where two are usedone may be readily removed and replaced without interfering with theoperation of the other, which is left in position to be used singly,

if so desired. The advantage in point of sim-V plicity and economy ofconstruction, by dis pensing with the end shoulders and bearings, is amaterial one, and, in addition thereto, the shoulders are removed froman exposed outer position to a comparatively secure inner one. It willbe seen, further, that the shoulders are unaffected in position by thestretching of the cutters that may from time to time be necessary tokeep them up to standard size, and are exempt from their formerliability to breakage in hardening or in use, and that thestrength anddurability of the cutters are promoted by the substitution of a singleclosedended passage for the two open recesses heretofore employed.

I claim as my invention and desire to secure by Letters Patentl. Thecombination, substantially as set forth, of a transversely-slottedboring-bar, a tool oncutter having formed through its body a centralhole or passage suited to admita cutter of less depth, and aclamping-screw.

2. The combination, substantially as set forth, of atransversely-slotted boring-bar, a

tool or cutter having a central bearing projection and fitting in theslot of said bar, a bearing located centrally in said bar and abuttingagainst the bearing projection of the cutter, and a clamping-screwbearing against the opposite face of said cutter.

3. 'Ihe combination, substantially as set forth, of a boring-bar havingtwo diametric slots at right angles one to the other, a tool or cutterhaving a central bearing projection on one of its sides, and having ahole throughit, said cutter tting in one of the diametric slots of saidbar, a cutter having a central bearing projection on one of its sides,said cutter passing through' and bearing against the opening of thecutter first specied and through the opposite slot of the bar, bearingslocated centrally in said bar and abutting against the .bearingprojections ofthe cutters, and a clamping-screw bearing against the faceof. the cutter first specified opposite its bearing proj ection.

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4. The combination7 substantially as set forth7 of a boring-bar havingtwo dianietrio slots at right angles one with the other, ashoulder-block fixed in a central opening in said bar, above the slotsthereof, a pair of tools or cutters fitting in the slots of the bar,each of said cutters havinga central bearing projection on one of itssides abutting against a seat or face on the shoulderblock, and one ofsaid cutters being passed through a central opening or passage in theother cutter, and a clamping screw or key bearing against the cutterWhich is provided with said opening or passage.

LUTHER ,1%. FAUGHT.

Vitnesses:

J. SNOWDEN BELL, GHAs. E. Pnnoonsr.

